The number9,223,372,036,854,775,807 is an integer equal to 263 − 1. Although of the form 2n − 1, it is not a Mersenne prime. It has a factorization of 72 · 73 · 127 · 337 · 92737 · 649657, which is equal to Φ1(2) · Φ3(2) · Φ7(2) · Φ9(2) · Φ21(2) · Φ63(2).

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The number 9,223,372,036,854,775,807, equivalent to the hexadecimal value 7FFF,FFFF,FFFF,FFFF16, is the maximum value for a 64-bitsigned integer in computing. It is therefore the maximum value for a variable declared as a long integer (long, longlongint, or bigint) in many programming languages running on modern computers. The presence of the value may reflect an error, overflow condition, or missing value.

This value is also the largest positive signed address offset for 64-bit CPUs utilizing sign-extended memory addressing (such as the AMD x86-64 architecture, which calls this "canonical form" extended addressing). Being an odd value, its appearance may reflect an erroneous (misaligned) memory address. Such a value may also be used as a sentinel value to initialize newly allocated memory for debugging purposes.

The Cstandard library data type time_t, used on operating systems such as Unix, is typically implemented as either a 32-bit or a 64-bit signed integer value, counting the number of seconds since the start of the Unix epoch (midnight UTC of 1 January 1970). Systems employing a 32-bit type are susceptible to the Year 2038 problem, so many implementations have moved to a wider 64-bit type, with a maximal value of 263−1 corresponding to a point in time 292 billion years from now.

Other systems encode system time as a signed 64-bit integer count of the number of ticks since some epoch date. On some systems (such as the Java standard library), each tick is one millisecond in duration, yielding a usable time range extending 292 million years into the future. On other systems (such as Win32), each tick is 100 nanoseconds long, yielding a time range of ±29,227 years from the epoch.

An error in the PayPal payment system in July 2013 accidentally debited $92 quadrillion from the account of Chris Reynolds. (The exact amount debited was US$92,233,720,368,547,940.25, just $182.18 more than 263−1 cents, resulting in a net balance of −US$92,233,720,368,547,800.00). PayPal corrected the error, and offered to make a donation to a charity of Reynold's choice.[1]

In 2014 the number of views on the video Gangnam Style on YouTube began approaching the maximum value of a 32-bit integer. This forced Google to upgrade to using 64-bit registers to hold the number of views for a video.[2]